SVG import/export is greatly improved. That will be not much collapsed by InkScape editing.

The document should be 256 x 256 px

JKnoMan will import only 'Path'. Objects for example characters should be converted to path

Framemask-Maskbits mode can specify the visibility frame-by-frame with '0' or '1'. This mode will be handy for switches that has few frames, especially NI Kontakt's 6 frame image (off/on/pressOff/pressOn/hoverOff/hoverOn).
For example, '001100' specify visible only 2 and 3 frame.